Unknown Rock Specimen
igneous
Category
Not A Rock (Man Made Origin)
Browse not a rock (man made origin) specimens identified by the Rock Identifier community.
Quartz-veined Mudstone or Argillite
SiO2 (Quartz) in Siltstone/Mudstone matrix
sedimentary
Quartz in Matrix (possibly Basalt or Siltstone host)
Silicon Dioxide (SiO2) in Host Rock
mineral
Quartz (Druzy)
Silicon Dioxide (SiO2)
mineral
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Basalt
Basalt (Aphanitic-fine grained mafic igneous rock)
igneous
Thunderegg (Ate Agate/Jasper Geode)
Silicon Dioxide (SiO2) within Rhyolite/Perlite matrix
sedimentary/igneous intermediary
Quartz Vein in Host Rock
Quartz (SiO2) in Mafic or Sedimentary Matrix
igneous
Sandstone
Arenite
sedimentary
Sandstone
Sandstone (clastic sedimentary rock)
Rock
Basalt (Amygdaloidal)
Amygdaloidal Basalt
igneous
Sandstone with Quartz Veins
Arenite (primarily SiO2 with Fe2O3 staining)
sedimentary
Botryoidal Chalcedony (Desert Rose / Agate)
Silicon Dioxide (SiO₂)
Mineral variant
Yellow Quartzite
Quartzite (SiO2 with iron oxide inclusions)
metamorphic
Quartzite (Water-worn Cobble)
Quartzite (Composition: 90%+ SiO2)
metamorphic
Basalt
Basalt
igneous
Banded Slate or Siltstone with Quartz/Calcite Veins
Protolith-derived Siltstone or Slate (varies based on degree of metamorphism)
metamorphic
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
River Pebble (Gravel)
Clastic sedimentary rock (likely Siltstone or Mudstone pebble; SiO2 with various impurities)
sedimentary
Sandstone with Quarzite clasts
Arenite (SiO2 based)
sedimentary
Chert (Agatized/Chalcedony variety)
Microcrystalline Quartz (SiO2)
sedimentary
Red Swirl Beads (Likely Resin or Glass, simulating Red Jasper or Agate)
N/A (for the beads as pictured); Red Jasper: SiO2 (Chert variety); Red Agate: SiO2 (Chalcedony variety)
Organic (if resin) or Synthetic (if glass); simulating Sedimentary or Metamorphic (for natural stones)
Pebble or Cobble (likely composed of sandstone or conglomerate)
Clastic Sedimentary Rock (specific name like sandstone, conglomerate, or breccia would require microscopic analysis of clast size and angularity)
Sedimentary Rock (possibly a conglomerate or coarse-grained sandstone)
Basalt
Afanitic Mafic Basalt
igneous
Granite
Granite (Mainly Quartz, Feldspar, and Mica)
igneous
Conglomerate
Conglomerate (Detrital Sedimentary Rock)
sedimentary
Vesicular Basalt (Scoria)
Vesicular Basalt
igneous
Ferruginous Sandstone (Ironstone)
Arenite with Limonite/Goethite cement
sedimentary
Serpentinite (often called Jade or Nephrite substitute)
Serpentinite (composed primarily of Antigorite, Lizardite, or Chrysotile)
metamorphic
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Moonstone
Orthoclase (Potassium Aluminum Silicate), Formula: (K,Na)AlSi3O8
mineral
Schist
Schist (metamorphic rock)
metamorphic
Agate Geode
Silicon Dioxide (SiO2)
mineral
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Chert (Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Wishing Stone with Quartz Veins
Quartzite or Quartz-veined Metamorphic Rock (composed mainly of SiO2)
metamorphic
Basalt with Quartz/Calcite Vein
Amygdaloidal Basalt (matrix) with Mineral Vein filling
igneous
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily Quartz, SiO2)
sedimentary
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Peach Moonstone
Potassium Aluminum Silicate (KAlSi3O8)
mineral
Druzy Quartz on Host Rock
Silicon Dioxide (SiO2)
mineral